In §C.12, the theory of multiport scattering was derived, i.e.,
the reflections and transmissions that occur when
digital
waveguides having wave impedances
are connected together. It
was noted that when
is a power of two, there are
no multiplies in the scattering relations Eq.(C.105), and that
this fact has been used to build multiply-free reverberators and other
structures using digital waveguide meshes
[434,520,147,399,522,523,401,402,404,55,203,324,323,325,426,33].